Phytochemicals

anti-oxidants

The anti-oxidant vitamins are electron donors capable of decreasing the number of
free radicals in the body, blood, spaces within tissues, and even within cells where
they are the most dangerous. The mechanism for this has been worked out. Free
radicals are usually multi-atom chemical substances which have lost an electron and
become ionized, although some minerals can also exist as free radicals. The free
radicals can take up electrons from any location where they can be easily accessed.
Remembering that nitrogenous compounds (proteins) are highly unstable, they provide
excellant electron donors for free radicals to ‘steal’ electrons from.
This, of course, breaks a peptide bond (the chemical reaction breaking the peptide
bond is an oxidation reaction, and the free radical is reduced), producing two
polypeptides (without the biological significance which made them proteins in the
first place). If the proteins were structural, then structural damage results
requiring repair using available amino acids. If the proteins were enzymatic, the
enzymatic function ceases sooner than expected, and may compromise whatever function
would have been supplied had the enzymatic function continued. The alternative to the
damaging effects of free radicals is for an anti-oxidant (such as Vitamin C, Vitamin
E, or beta-carotene) to intercept the free radical, reduce it (preventing damage),
but this also oxidizes the vitamin (or other anti-oxidant) thereby destroying the
anti-oxidant. This also explains why Vitamins A, C and E are needed on a daily basis
rather than weekly as for most nutrients. Tobacco and tobacco smoke [first-hand or
second-hand] contain “substances known to the State of California…”
which can be absorbed into the blood from the lining of the respiratory system as
well as the lining of the digestive system [not limited to the intestines] and
which are very effective free radicals, so tobacco users [including
‘smokeless’ tobacco products, and even most products used to aid smoking
cessation] require more Vitamin A, C, and E than do non-smokers (but non-smoking
requires not inhaling second-hand smoke). There is little doubt that these processes
(damage due to free radicals, and the capability of anti-oxidants to disable the free
radicals) actually occur in living tissues.

&nbsp &nbsp The claim that anti-oxidants can repair damage due to
oxidation of essential chemicals can not be explained as easily as the protective role
of anti-oxidants. Most of the mechanisms for causing the repair of the damage caused
by free radicals involve known metabolic processes, so the anti-oxidant would have to
be a co-enzyme for that particular metabolic process in order for the anti-oxidant to
assist in the repair [not drive, read “cause,” the repair]. The role
of Vitamin C in lessening the symptoms of the common cold would have to be the
reduction of bacterial or viral toxins by the anti-oxidant properties of the
Vitamin C [assuming, these toxins behave as free radicals]. This could serve,
at best, to lower the toxin concentration, and therefore the amount of damage inflicted
by the toxins. Assuming that the role of Vitamin C in preventing the symptoms
of the common cold is true [not a good assumption] rather than
an example of the placebo effect [a much better assumption], the mechanism of action
would have to be the reduction of critical biochemicals in the bacteria or viruses
(there are about 3,000 such bacteria and viruses) responsible for the common cold;
and this has not been shown to happen in a living organism. Two minerals, Zinc and
Selenium have been cited as minerals with anti-oxidant properties which could be
effective in relieving cold symptoms. Unfortunately, if either of these minerals were
to have this effect, the mineral would be oxidized from its atomic state [no charge on
the atom] to a free radical, which in turn could inflict damage somewhere else. Since
both Zinc and Selenium can easily become charged ions (a.k.a. free radicals), they
happen to be rather toxic [Selenium, for example, is the active ingredient in
‘loco weed,’ which produces severe psychosis (brain chemistry) problems for
cattle; Selenium also causes (pg. 23-9 in the text) abnormal brain function
(irritability) in Humans].

Anti-oxidants &amp the French Paradox

We have already met the French Paradox (last lecture): the French eat delicious flaky
pastries made with animal lard, and filled with dairy-based fillings, providing too
much cholesterol and saturated fats [and should exhibit a high incidence of
artherosclerosis], but are heart-healthy. They also drink too much [mostly wine,
usually red wine]. So, we wondered, does drinking red wine allow them to completely
ignore the USDA's food guide pyramid? without consequences? Since red wine appears to
exhibit a greater effect than do the white wines, and red wines are made from grapes
with skins, and white wines are made from grapes with the skins removed, the obvious
place to look for the active ingredient is in the skins. When we examined the grapes
skins, we found a high concentration of anti-oxidants, such as reveratrol (see any of
the Roizen &amp Oz books, and look up either red wine or reveratrol in the index).
Similarly, the Italians consume large amounts of pasta made with animal fats (and
whole grains) plus lots of tomato-based sauces &amp olive oil (an Ω-3 oil) [not to
mention drinking more wine than most American health professionals consider
reasonable], and remain heart healthy. Tomatoes turn out to be high in anti-oxidants,
but at lower density then in grape skins. Turning our attention to the two large
populations with the highest life expectancies [age at which 50% of the same aged
population can be expected to die (a concept borrowed from the Insurance Industry)],
Japan and Hong Cong, we find that they consume very large quantities of green
vegetables which have been cooked quickly in hot Ω-3 oils [stir frying using a
wok] so they remain crisp even after cooking and, more importantly, retain virtually
all their nutrients [American-style over-cooked vegetables have most of the nutrients
‘cooked out’ of them], plus lots of Ω-3 fish (white fish). The darker
green vegetables have the highest anti-oxidant density of all vegetables. The common
feature of these diets is high anti-oxidants and Ω-3 oils. The obvious hypothesis
is that the combination of anti-oxidants and Ω-3 oils cause the heart health
needed to achieve long life expectancies and long life spans. Current research is
testing this hypothesis.

phytochemicals

The popularity of the anti-oxidants led to similar claims for many other
plant-derived chemicals [given the catchy name phyto-chemicals]. Phyto-chemicals were [and still are] heavily
promoted by Herbalists. The Ethnobotanists (the Botany discipline which studies
“Folk remedies” from regional plants), Nutritionists and medical
researchers interested in wellness are currently examining the phytochemicals to
determine if the health claims for them are justified. Their results thus far have
been sufficiently encouraging that the phytochemicals have become credible enough to
start appearing in Nutrition textbooks and lectures. However, all of the research thus
far (and it is currently “inconclusive”) suggests that the phytochemicals
taken as food (dark green leafy vegetables, cruciferous vegetables [broccoli,
cauliflower, brussel sprouts]) provide a far greater benefit than do the plant
extracts taken as supplements in tablet form. Some of the supplement tablets show no
positive benefits, while others show only slight effects [below statistical
significance]. Some authors are now speculating that the phytochemicals will
eventually be added to the list of nutrient classes important to optimal Human
functioning. Although I am not surprised that the benefits of phytochemicals are
higher from food than from tablets, I am not prepared to accept the phytochemicals as
nutrients [until more research supports the health benefit claims for the
phytochemicals]. I would also like to see some explanation of the physiological
mechanisms by which they work.

&nbsp &nbsp The phytochemicals technically include all chemicals
found in plants: the pigments &amp accessory pigments, enzymes &amp co-enzymes,
hormones &amp hormone-like substances, cellulose &amp lignin in cell walls, the
toxins that protect plants from insect [and other animals] damage &amp fungal
diseases of plants, and even DNA. In practice, most of the “phytochemicals”
with proposed health benefits are pigments, accessory pigments, enzymes, and
co-enzymes [but a few are toxins]. One group of phytochemicals which are claimed to
“speed up your metabolism” as a means of losing weight without changing
either your eating or exercise habits are the co-enzymes of the electron transport
system (where energy is finally captured as ATP). These claims are highly seductive,
but your mitachondrial DNA includes all of the genes for all of these co-enzymes, and
as a result every mitachondrion you own already has all the co-enzymes it needs (or
can use); you could speed up your metabolism by growing more mitachondria [but you
have to wait until the “Weight Management 2” lecture to find out how to do
this].

footnote: the Welch's ads promoting their Concord grape juice cite reports
from the USDA in support of their claims. You need to know that the USDA
publishes pamphlets written by individuals not employed by the USDA, and not
fact-checked by USDA personnel. The individual who wrote the pamphlets cited by
Welch's is Welch's [the IRS promulgated regulations allowing treatment of
corporations as individuals for tax purposes, because the IRS can tax income only of
individuals; this regulation also causes corporations to be treated as individuals by
all Federal agencies]. The pamphlets describing the anti-oxidant properties of
concord grape juice were neither written by nor endorsed by the USDA, but merely
published by the USDA. This statement does not say anything about the accuracy of the
information in the pamphlet, only the nature of the source of the pamphlet. Since
Concord grape juice is made from grapes with skins included, the anti-oxidant levels
are probably very high.

Genetically modified (GM) foods

Technically, all food from agricultural sources is genetically modified,
because we have been using selective breeding to ‘improve’ food organisms
for at least 5,000 years. According to an article in Science, “Maize [corn]
was domesticted from Balsas teosinte (Zea mays ssp parviglumis ~9000 years
ago, resulting in a wide variety of [different breeds]” (Jean-Philippe Vielle-Calzada,
et al. The Palomero Genome Suggests Metal Effects on Domestication, Science
vol 326 [20 November 2009]: p. 1078) This pushes the time frame for selective breeding
4,000 years further back than previous estimates!
However, the opponents of “genetically modified”' foods
are actually referring to genetic engineering, where beneficial genes from one species
are spliced into the genome of another species. For example, some plants which were
not Vitamin C sources have been genetically engineered to produce Vitamin C. The
opposition to genetically engineered foods seems to have become a issue after a
reporter in Europe used the expression “franken-tomatoes” to describe a
genetically engineered tomato. This was, of course, a reference to Mary Shelly's
famous book about a mad scientist who created a monster in his laboratory [the
monster was not ‘Frankenstein;’ the mad scientist was Dr. Frankenstein; in
fact, the monster had no name], and conjured up images that struck fear in the minds
of some readers. Thus far, most of the genetic engineering accomplishments have been
to add the ability to produce toxins for the control of insect pests. You should know
that one of the most effective insecticides known is nicotine. Because the physiology
of insect external respiration (breathing) is different from that of vertebrates,
nicotine causes respiratory arrest in insects. A very effective means of getting rid
of household ants is to put tobacco in a jar filled with water, and make a ‘sun
tea’ from the tobacco. This “tea” can be sprayed around the foundation
of the house, and ants entering or leaving the house will absorb the nicotine through
their feet [I told you tobacco toxins can be absorbed through ‘unusual’
surfaces], and go into respiratory arrest. The down side is that this pesticide
application has to be repeated if it rains. I have successfully gotten rid of ants
over a three year period by this treatment. [this is intended to be useful trivia].
&nbsp &nbsp There is no evidence that GM foods are unsafe, but little credible
evidence that they are safe [since the ability to produce toxins has been added to
food plants]. I doubt that the controversy over GM foods will go away in most of your
life times.